1. Field
Exemplary embodiments relate to a display device. More particularly, exemplary embodiments relate to a display device with an improved level of display quality with fewer numbers of defects.
2. Discussion of the Background
With the development of multimedia, the importance of display devices is increasing. Accordingly, various types of display devices, such as liquid crystal displays (LCDs) and organic electroluminescent display devices are being used.
In an LCD, an electric field is applied to a liquid crystal material having negative dielectric anisotropy between two substrates. By controlling the intensity of the electric field, the amount of light (from an external light source) transmitted through the substrates is adjusted, thereby obtaining a desired image signal.
Generally, an organic electroluminescent display device emits light by electrically exciting a fluorescent organic compound. The organic electroluminescent display device may display an image by driving a plurality of organic light-emitting diodes (OLEDs) arranged in a matrix using voltage programming or current programming. Methods of driving the organic electroluminescent display device include a passive matrix method or an active matrix method using thin-film transistors (TFTs). In the passive matrix method, anodes and cathodes are formed to be orthogonal to each other, and lines are selected to be driven. On the other hand, in the active matrix method, a TFT is connected to each indium tin oxide (ITO) pixel electrode and driven according to a voltage maintained by the capacitance of a capacitor connected to a gate of the TFT.
A defect detection process must be performed before an electronic device using a display device is finally produced. In the defect detection process, a plurality of pixels formed in the display device may be illuminated to determine whether the display device operates normally.
In the defect detection process performed by illuminating a plurality of pixels, a test voltage is generally applied to each pixel to identify whether there are defective pixels. However, while defective pixels can be detected, other defects, such as fractures and cracks existing in a region other than the region in which the pixels are formed, might not be detected. Even if the display device is determined to be non-defective in the pixel illumination test, other defects, such as fractures and cracks existing in the region other than the region in which the pixels are formed, can later increase in number, or moisture can penetrate into the display device through the fractures and cracks. In such cases, the operation or performance of the pixels may be adversely affected.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the inventive concept, and, therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.